Former National Intelligence Director James Clapper, accompanied by former acting Attorney General Sally Yates, testifies on Capitol Hill in Washington, Monday, May 8, 2017, before the Senate Judiciary subcommittee on Crime and Terrorism hearing: “Russian Interference in the 2016 United States Election.” (AP Photo/Pablo Martinez Monsivais)

WASHINGTON (AP) — American democracy is “under assault” on separate fronts from President Donald Trump and Russia, the former U.S. intelligence chief warned Sunday, expressing dismay over the abrupt firing of FBI director James Comey amid a probe into Moscow’s meddling in U.S. elections and possible ties with the Trump campaign.

As Trump works to fast-track Comey’s successor, lawmakers from both parties urged him to steer clear of any politicians for the job and say he must “clean up the mess that he mostly created.”

“I think, in many ways, our institutions are under assault, both externally — and that’s the big news here, is the Russian interference in our election system,” said James Clapper, the former director of national intelligence. “I think as well our institutions are under assault internally.”

When he was asked, “Internally, from the president?” Clapper said, “Exactly.”

Clapper spoke following Trump’s sudden firing of Comey last week, which drew sharp criticism because it came amid the FBI’s investigation into Russia’s interference in the 2016 presidential election. Clapper said America’s founding fathers had created three co-equal branches of government with checks and balances, but with Trump as president, that was now “eroding.”

The White House had no immediate comment. No White House aide appeared on the Sunday news shows, leaving Nikki Haley, the U.S. ambassador to the United Nations, to defend Trump. “The president is the CEO of the country. He can hire and fire whoever he wants,” she said.

Lawmakers from both parties reprimanded Trump’s actions, which included shifting explanations from the White House for Comey’s dismissal and an ominous tweet by Trump that warned Comey against leaks to the press because he may have “tapes” of their conversations. The lawmakers called for a new FBI director without any political background and said Trump would need to hand over to Congress any taped conversations with Comey, if they exist.

Republican Sen. Lindsey Graham, a member of the Judiciary Committee, said selecting an FBI agent to lead the agency would allow the nation to “reset.” He dismissed as less desirable at least two of the 14 candidates under consideration by Trump, former Rep. Mike Rogers of Michigan and Sen. John Cornyn of Texas, explaining that “these are not normal circumstances.”

Rogers, an ex-FBI agent and former chairman of the House Intelligence Committee, has drawn the backing of the FBI Agents Association. Cornyn is the No. 2 Republican in the Senate.

“It’s now time to pick somebody who comes from within the ranks, or has such a reputation that has no political background at all that can go into the job on Day 1,” said Graham, R-S.C.

“The president has a chance to clean up the mess he mostly created,” he said, adding, “I have no evidence that the president colluded with the Russians at all … but we don’t know all the evidence yet.”

Sen. Mike Lee, a Republican from Utah, continued to argue that the president should consider Merrick Garland — the federal judge nominated to the Supreme Court last year by President Barack Obama. Lee said he was “absolutely serious about it.”

A former top aide to Sen. Mitch McConnell, Josh Holmes, said McConnell is interested in the suggestion. “I think the Senate majority leader thinks that’s a fantastic idea,” Holmes said. Garland never got a hearing due to Republican obstruction, and the high court vacancy was filled last month by Neil Gorsuch.

Senate Minority Leader Chuck Schumer of New York said the new FBI director should be someone “not of partisan background” with “great experience” and “courage.” Declining comment on a Garland nomination, Schumer left open the possibility that Democrats might withdraw support for a new FBI director unless the Justice Department names a special prosecutor. Under Senate rules, Republicans could still confirm an FBI director with 51 votes. Republicans hold 52 seats in the chamber to Democrats’ 48.

Calling Trump’s remarks about possible taped conversations “outrageous,” Sen. Mark Warner of Virginia, the top Democrat on the Senate Intelligence Committee, said his panel or another committee would “absolutely” subpoena the tapes.

“We have got to make sure that these tapes, if they exist, don’t mysteriously disappear,” Warner said, adding that he hopes to have Comey testify in a public hearing before his committee.

Less than a week after Trump fired Comey, the administration has interviewed at least eight candidates to be FBI director, and Trump has said a decision could come before he leaves Friday on his first overseas trip as president.

Trump abruptly fired Comey on Tuesday and later said Comey was a “showboat” and “grandstander” who was not doing a good job. Trump said in an interview with NBC that the Russia investigation factored into his decision to fire Comey.

The FBI director serves a 10-year term but can be replaced by the president.

So far 14 people have emerged as candidates. Eight met at the Justice Department on Saturday with Attorney General Jeff Sessions and his deputy, Rod Rosenstein:

–Alice Fisher, a high-ranking Justice Department official in the George W. Bush administration.

–Adam Lee, special agent in charge of the FBI’s office in Richmond, Virginia.

— Andrew McCabe, the acting FBI director.

–Michael J. Garcia, a former prosecutor and associate judge on New York’s highest court.

–Cornyn, a former Texas attorney general.

–U.S. District Judge Henry E. Hudson, a Bush appointee who struck down the centerpiece of the Obama administration’s health care law in 2010.

–Frances Townsend, a former Bush homeland security and counterterrorism adviser.

–Rogers. The FBI Agents Association says it believes his diverse background makes him the best choice.

Clapper and Schumer made their comments on CNN’s “State of the Union”; Graham spoke on NBC’s “Meet the Press”; Haley and Warner appeared on ABC’s “This Week” and Warner also spoke on “Fox News Sunday” along with Lee and Holmes.